Replaceable drop-outs enable you to convert Intense's Carbine into a 650B rig. We give it a go.

650B/27.5—whatever you want to call it—is the cause célèbre of the mountain bike world these days. Norco, Intense, Rocky Mountain, Scott, Jamis and a host of other bike companies have 27.5-inchers in their 2013 line-ups. Likewise, anyone and everyone in the business of selling forks and tires has come out with 27.5-compatible widgets.

So, there you have it: the next big thing. Or the next mid-sized thing. Or just the latest, lemmings running off a giant effin’ cliff thing.

It can be hard to say which is which at times.

While part of me dies every time I see a 27.5-wheeled hardtail (Seriously, you couldn’t make a 29er hardtail with a reasonable chainstay length? Really? Are you just not trying?), I think there is merit to the idea of adding 27.5-inch wheels to all mountain bikes. The bigger-than-26 wheels bring benefits, without adding as much weight or adding miles to the chainstays (which is generally the result of grafting 29er hoops onto a bike with six inches of rear suspension travel).

Thus, I was intrigued when I heard that Intense was offering conversion G1 dropoouts that kick your axle up and back a bit and allow you to squeeze in a 27.5-inch rear wheel into the back end of either a Carbine or Tracer 2.

This is all it takes to convert our Carbine to 650B. Well, that and a fork, some tires and a wheelset, but still, it's pretty cool that this is an option at all.

Pricing for said kit (which includes 142×12 Syntace dropouts, a DT Swiss RWS 142×12 axle and an extended brake adapter)? Two hundred bucks.

Of course, you still need to score a new fork and a new wheelset and, once you’ve done that, you’ll have pillaged your checking account, but still, if you dig your existing Intense and want to improve the bike’s roll-over abilities without jacking up its geometry, this is an interesting potential upgrade.

Which is why I got a set and slapped them on our Carbine test bike. Jason Moeschler at WTB was kind enough to pitch in some wheels. Schwalbe kicked in some 650B Hans Dampfs and RockShox sent over a Revelation.

Here's that Carbine--this time with 27.5-inch wheels and a RockShox Revelation 650B fork. Still fun, still flickable, but a bit less of a handful in rock gardens and the like.

The conversion itself amounted to two minutes of labor that could be performed by a very slow chimpanzee. Unbolt old dropouts. Bolt on new dropouts. Change brake adaptor. Done. Sweet.

How did it ride? Well, for the whole spiel, you’ll need to check out the December issue of Bike, but if I were to sum it up, I’d say the Carbine 275 was noticeably better in all the places you’d expect it to excel (rock gardens, root sections, ledges), but it’s not the kind of night and day difference that you experience with a 29er. Not a huge revelation, right? These are in–betweener wheels after all.

The flipside, however, is that the bike really didn’t feel too different from its 26er incarnation when it came to threading the needle on tight sections. If you hate the way 29ers feel, but like the idea of gaining a longer contact patch and better angle of attack on your all mountain bike, then 27.5-inch wheels are worth considering.